The overarching purpose of this proposal is to establish the concordance between clinical parameters and vision specific quality of life (QOL) using the extensive, longitudinal dataset available from the Collaborative Initial Glaucoma Treatment Study (CIGTS). We will be addressing the following specific aims: Aim #1: To explore whether binocular clinical measures correlate more strongly than monocular measures with patients' perceptions of their visual function. The binocular measures which will be considered include the Esterman visual field (VF) score, simulated measures of the binocular VF, and the binocular visual acuity (VA) score; the monocular measures include the better and worse eye VF and VA scores. Aim #2: To establish the relationship between the location of VF damage and patients' appraisal of their visual function. For example, are patients more likely to experience problems reading small print if they have central and/or paracentral VF loss; or are patients who report trouble changing lanes in traffic or seeing objects coming from the side more likely to have experienced peripheral VF damage? Aim #3: To determine if the relationship between VF progression and patients' perceptions is linear, or must damage progress beyond a certain threshold before patients can discern changes in their visual function. Aim #4: To compare and contrast the various vision-specific QOL measures (i.e., VAQ, NEI-VFQ, and Symptom Impact-Visual Function subscale) in terms of the strength of their responsiveness to clinically relevant VF progression and changes in VA.